A water rocket is a type of model rocket using water as its reaction mass. The pressure vessel—the engine of the rocket—is usually a used plastic soft drink bottle. The water is forced out by a pressurized gas, typically compressed air. The term "aquajet" has been used in parts of Europe in place of the more common "water rocket" and in some places they are also referred to as "bottle rockets" (which can be confusing as this term refers to a firework in other places). The bottle is partly filled with water and sealed. The bottle is then pressurized with a gas, usually air compressed from a bicycle pump, air compressor, or cylinder up to 125 psi, but sometimes CO2 or nitrogen from a cylinder. Water and gas are used in combination, with the gas providing a means to store potential energy, as it is compressible, and the water increasing the mass fraction and providing greater momentum when ejected from the rocket's nozzle. Sometimes additives are combined with the water to enhance performance in different ways. For example: salt can be added to increase the density of the reaction mass resulting in a higher specific impulse. Soap is also sometimes used to create a dense foam in the rocket which lowers the density of the expelled reaction mass but increases the duration of thrust. It is speculated that foam acts as a compressible liquid and enhances the thrust when used with De Laval nozzles. The seal on the nozzle of the rocket is then released and rapid expulsion of water occurs at high speeds until the propellant has been used up and the air pressure inside the rocket drops to atmospheric pressure. There is a net force created on the rocket in accordance with Newton's third law. The expulsion of the water thus can cause the rocket to leap a considerable distance into the air. Typically launch pressures vary from 75 to 150 psi (500 to 1000 kPa). The higher the pressure, the larger the stored energy. The current record for greatest height achieved by a water and air propelled rocket is 2044 feet (623 meters), held by U.S. Water Rockets on June 14, 2007. This altitude was calculated by averaging two flights. The first flight achieved 2068 feet (630 meters) and the second 2020 feet (615.7 meters). The rocket also carried an onboard video camera on both flights. [READ THE REST OF THIS ARTICLE]

The Haunted Mansion is a dark ride located at Disneyland, the Magic Kingdom at Walt Disney World, Tokyo Disneyland, and Disneyland Park in Paris (as Phantom Manor). Each incarnation of the attraction features a ride-through tour of a haunted house in Omnimover vehicles called Doom Buggies, preceded by a walk-through show in the queue. The attraction showcases a number of age-old tricks, advanced special effects, and spectral Audio-Animatronics. The attraction's roots date back to even before Disneyland was built, when Walt Disney had just hired the first of his Imagineers. The first known illustration of the park showed a main street setting, green fields, western village, and a carnival. Disney Legend Harper Goff developed a black-and-white sketch of a crooked street leading away from main street by a peaceful church and graveyard, with a run-down manor perched high on a hill that towered over main street. While not part of the original attractions when Disneyland opened in 1955, Disney assigned Imagineer Ken Anderson to make a story around the Harper Goff idea and the design of his new 'grim grinning' adventure. Plans were made to build a New Orleans-themed land in the small transition area between Frontierland and Adventureland. Weeks later, New Orleans Square appeared on the souvenir map and promised a thieves' market, a pirate wax museum, and a haunted house walk-through. After being assigned his project, Anderson studied New Orleans and old plantations to come up with a drawing of an antebellum manor overgrown with weeds, dead trees, swarms of bats, and boarded doors and windows topped by a screeching cat as a weathervane. On May 3, 2006, new changes went into effect at the Disneyland Haunted Mansion. The new show scene introduced in the attic scene during the ride follows a ghostly bride named Constance Hatchaway (portraits played by Buffy The Vampire Slayer actress Julia Lee and voiced by Kat Cressida), now described as a "black widow bride," and slowly uncovers her bloody past, which includes the murders and decapitations of all her previous husbands (named Ambrose Harper, Frank Banks, Reginald Caine, the Marquis De Doom, and George Hightower) in an attempt to gain their vast fortunes. The new effects start when visitors first enter the mansion's attic. Now, when the visitor enters the attic, the pop-up ghosts that shout "I do!" are gone. This is to make room for the current effects. As the visitor enters the attic, the first new things seen are an amber-glowing glass lamp, various treasures and china, and multiple portraits of different grooms, each with the same bride. An axe-like sound echoes from the pictures throughout the room, and in each portrait the groom's head disappears. [READ THE REST OF THIS ARTICLE]

The fire knife is a traditional Samoan cultural implement that is used in ceremonial dances. It was originally composed of a machete wrapped in towels on both ends with a portion of the blade exposed in the middle. Tribal performers of fire knife dancing (or Siva Afi as it is called in Samoa) dance while twirling the knife and doing other acrobatic stunts. The towels are set afire during the dances thus explaining the name. Knife dancing has a history which goes back hundreds of years. The modern fire knife dance has its roots in the ancient Samoan exhibition called "ailao" - the flashy demonstration of a Samoan warrior's battle prowess through artful twirling, throwing and catching, and dancing with a war club. The 'ailao could be performed with any warclub and some colonial accounts confirm that women also performed 'ailao at the head of ceremonial processions, especially daughters of high chiefs. During night dances torches were often twirled and swung about by dancers, although a warclub was the usual implement used for 'ailao. Before the introduction of metals, the most common clubs that were wielded and displayed in the 'ailao fashion were elaborately carved heirloom clubs called "anava." These 'anava were frequently carved with serrated edges and jagged "teeth" which characterized the unique Samoan weapon called the "nifo'oti." When European and American whalers and traders began commercial ventures in Samoa they introduced the natives to the long-handled blubber knife and the hooked cane knife. The characteristic metal hook of these tools was readily incorporated into the Samoan wooden nifo'oti which bears the unique hooked element whether carved from wood or forged from steel. One common claim is that the word "nifo'oti" means "tooth of death" but this is not linguistically accurate as Samoan syntax places the modifier after the subject; according to Samoan grammar the term "nifo'oti" would actually mean "dead tooth," hardly as intimidating as the former translation. Fire was added to the knife in 1946 by a Samoan knife dancer named Freddie Letuli, later to become Paramount Chief Letuli Olo Misilagi. Letuli was performing in San Francisco and while practicing, noticed a Hindu Fire eater and also a little girl with lighted batons. The fire eater loaned him some fuel, he wrapped some towels around his knife, and the fire knife dance was born. Although today many commercial performers perform the dance with short staffs or unbladed knives, this is not authentic fire knife dance and is unacceptable in the Samoas except for training purposes. The knives used by performers in American Samoa are still made of machetes, although they are often dulled for younger dancers. [READ THE REST OF THIS ARTICLE]

Manfred Albrecht Freiherr von Richthofen (2 May 1892 – 21 April 1918), widely known as the Red Baron, was a German fighter pilot with the Imperial German Army Air Service (Luftstreitkräfte) during World War I. He is considered the ace-of-aces of that war, being officially credited with 80 air combat victories, more than any other pilot. Originally a cavalryman, Richthofen transferred to the Air Service in 1915; becoming one of the first members of Jasta 2 in 1916. He quickly distinguished himself as a fighter pilot, and during 1917 became leader of Jasta 11 and then the larger unit Jagdgeschwader 1 (better known as the "Flying Circus"). By 1918 he was regarded as a national hero. Richthofen championed the development of the Fokker D.VII with suggestions to overcome the deficiencies of the then current German fighter aircraft. However, he never had an opportunity to fly it in combat as he was killed just days before it entered service. Richthofen was shot down and killed near Amiens on 21 April 1918. There has been considerable discussion and debate regarding aspects of his career, especially the circumstances of his death. At the time, the Baron had been pursuing (at very low altitude) a Sopwith Camel piloted by a novice Canadian pilot, Lieutenant Wilfrid "Wop" May of No. 209 Squadron, Royal Air Force. In turn, the Baron was spotted and briefly attacked by a Camel piloted by a school friend (and flight Commander) of May's, Canadian Captain Arthur "Roy" Brown, who had to dive steeply at very high speed to intervene, and then had to climb steeply to avoid hitting the ground. Richthofen turned to avoid this attack, and then resumed his pursuit of May. It was almost certainly during this final stage in his pursuit of May that Richthofen was hit by a single .303 bullet, which caused such severe damage to his heart and lungs that it must have produced a very speedy death. In the last seconds of his life, he managed to make a hasty but controlled landing in a field on a hill near the Bray-Corbie road, just north of the village of Vaux-sur-Somme, in a sector controlled by the Australian Imperial Force (AIF). One witness, Gunner George Ridgway, stated that when he and other Australian soldiers reached the aircraft, Richthofen was still alive but died moments later. Another eye witness, Sgt Ted Smout of the Australian Medical Corps, reported that Richthofen's last word was "kaputt". In common with most Allied air officers, Major Blake, who was responsible for Richthofen's remains, regarded the Red Baron with great respect, and he organised a full military funeral, to be conducted by the personnel of No. 3 Squadron AFC. He remains very possibly the most widely known fighter pilot of all, and has been the subject of many books and films. [READ THE REST OF THIS ARTICLE]